Field-induced magnetic circular x-ray dichroism in paramagnetic solids: a new magneto-optical effect

It is demonstrated that for paramagnetic solids an external magnetic field-in analogy to the magneto-optical Kerr effect in the visible regime of light-gives rise to a magnetic circular dichroism in x-ray absorption (MCXD). A detailed description of this new field-induced magneto-optical phenomenon is given. In particular it is shown that the resulting dichroic spectra may be used to deduce the spin and orbital susceptibility in a component resolved way by making use of a modified form of the MCXD sum rules.